Interest in small animal imaging has grown in recent years in step with developments in molecular medicine and, in particular, with the emergence of molecular imaging. Modalities such as positron emission tomography (PET) and single photon emission tomography (SPECT) are of considerable value to researchers concerned with external noninvasive imaging of molecular events in vivo. The much higher sensitivities of both SPECT and PET make possible in vivo imaging of tracers at physiological concentrations not possible at present with any other technology especially in deep tissues. While small animal imaging with PET has certainly proven its worth, SPECT offers many advantages including the ability to perform dual labeling studies, the potential for higher intrinsic resolution, 99mTc, the most useful radionuclide in diagnostic nuclear medicine, and iodine radioisotopes (125I and 123I) critical for emerging in vivo proteomics research. NIH-funded investigators and others supporting this application have need for radioactivity measurements in small animals. In some cases, these measurements will benefit from, if not require, the tomographic imaging capability or the higher resolution of a small animal PET/SPECT camera. In all cases, superior spatial and temporal biodistributions will be obtained with the sacrifice of fewer animals. That a single animal can act as its own control is a major advantage, for example in tumor and infection/inflammation studies in which the imaging target tissue is difficult to standardize. The co-registration of radioactivity distribution with anatomy by X-ray computed tomography (CT) is an invaluable asset not yet available commercially in all but one small animal PET camera. In summary, the advantage of PET and SPECT for non-invasive in vivo animal imaging is the vastly higher sensitivity for the detection of biological tracers especially in deep tissues. The preferred method of performing animal biodistributions is animal imaging and the preferred method of animal imaging is on a dedicated small animal camera with matching spatial resolution. We wish to purchase the GammaMedica PET/SPECT/CT camera, the only commercially available small animal camera capable of both PET and SPECT, and equipped with CT capability for anatomical registration and quantitation. This application describes an administration plan with a chain of command from a full-time PhD scientist reporting to a faculty member administrator, both of whom will report to the P.I. who, in turn, will report to an advisory committee. Questions of camera usage and methods of encouraging imaging at UMMS will be considered by the advisory committee of users and non-users that includes members with experience in animal care, administration, conflict resolution and small animal imaging. The P. I. and his collaborators wish to use the High-End Instrumentation Grant as a vehicle to establish the nucleus of a core facility at UMMS for small animal imaging. We believe that this application addresses the goals of the NIH in offering the RFA and the goals of UMMS to expand use on our campus of small animal imaging. [unreadable] [unreadable] [unreadable] [unreadable] [unreadable]